please help me on my physics hw ​

Answer:

The net force on the hockey puck is zero because it's acceleration is zero due to constant velocity.

The hockey will remain in it's uniform motion unless compelled by an external force.

Explanation:

[tex]from \: vector \: mechanics \\ a = \frac{dv}{dt} \\ but \: at \: constant \: velocity \\ \frac{dv}{dt} = 0 \\ hence : \: \: a = \frac{0}{dt} \\ a = 0[/tex]

Answer:

The answer is "a, c and b"

Explanation:

The energy change caused by an endothermic chemical reaction is the absorption of thermal energy. So, option B.

Endothermic reactions are defined as, those reactions in which the reactants take in heat energy from the environment to create products.

Here,

The endothermic reactions lower the temperature of their surrounding area, thereby creating a cooling effect.

When bonds in the reactants are broken, more energy is absorbed than is released when new bonds are generated in the products. This is known as an endothermic reaction.

A drop in the temperature of the reaction mixture is a characteristic of endothermic reactions.

In endothermic reactions, the enthalpy of the products of the reaction is greater than that of the reactants. Energy is absorbed from the surroundings.

Hence,

The energy change caused by an endothermic chemical reaction is the absorption of thermal energy.

To learn more about endothermic reactions, click:

https://brainly.com/question/23184814

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Explanation:

the other 40% is used to power the 60% making it only capable of 60% efficiency

Answer: If a car travels 300 km in 3 hours, then it’s speed will will be 100 km/hr. But in practical it depends upon type of car, condition of car, car's maximum speed and also the path in which car is travelling.. Because car can't travel in constant speed of 100 km/hr. So, if car have 120 km/hr as maximum speed than it's minimum speed will be 85–95 km/hr. And so the car travel 300 km in around 5 or 5 and half hours.

Answer:

[tex]\boxed {\boxed {\sf 130 \ Newtons }}[/tex]

Explanation:

Work is the energy transferred to or from an object when force is applied to cause displacement. It is the product of force and displacement.

[tex]W=F*s[/tex]

The displacement (s) is 8 meters and the work (W) is 1,040 Joules. Substitute these values into the formula.

[tex]1040 \ J= F* 8 \ m[/tex]

First, let's convert the units. This will make the question easier later on. 1 Joule is equal to 1 Newton meter, so the 1040 J of work equal 1040 N*m.

[tex]1040 \ N*m= F * 8 \ m[/tex]

Since we are solving for the force (F), we must isolate the variable. It is being multiplied by 8 meters and the inverse of multiplication is division. Divide both sides by 8 m.

[tex]\frac {1040 \ N*m}{8 \ m}= \frac{F * 8 \ m}{8 \ m}[/tex]

[tex]\frac {1040 \ N*m}{8 \ m}=F[/tex]

The meters cancel out, hence our earlier unit conversion.

[tex]130 \ N = F[/tex]

A force of 130 Newtons is used.

Answer:

A

Explanation:

Answer:

a

Explanation:

because red litmus paper turn blues under base or alkaline condition

Answer:

answer the question i have asked go to my account

Explanation:

can i get brainliest

Answer:

yes you can go on your account

Answer:

I assume you are referring to the standard atomic weight of the elements when you write atomic mass. No elements beyond uranium has a standard atomic weight. The reason is explained by the organization assigned responsibility for the assignment of standard atomic weights,the international Union of Pure and Applied Chemistry commission on isotopic abundances and atomic weights.

Answer:

true

Explanation:

Answer:

convex and 1 plane mirror

Answer: 14 speed of Earth around Sun I see 30 km/s. FALSE

15. Because car is in circle track, direction of velocity changes

And car is in accelerating motion. direction of acceleration points to

The centre of the circle. RIGHT

Explanation:

Answer:

1. La cantidad de materia que hay en el Universo es 3,53x10⁵⁴ kg.

2. Se necesitan 1,8x10²⁴ masas solares para completar la masa total del Universo visible.

Explanation:

1. La cantidad de materia del Universo se puede calcular a través de su volumen (V) y de su densidad (d):

[tex] d = \frac{m_{u}}{V} = \frac{m}{\frac{4}{3}\pi r^{3}} [/tex]

En donde:

r: es el radio = d/2 = 8,8x10²⁶/2 m = 4,4x10²⁶ m

[tex]m_{u}[/tex]: es la masa del Universo =?

d: es la densidad = 9,9x10⁻²⁷ kg/m³      

[tex]m_{u} = d*v = 9,9 \cdot 10^{-27} kg/m^{3}*\frac{4}{3}\pi (4,4 \cdot 10^{26} m)^{3} = 3,53 \cdot 10^{54} kg[/tex]

Entonces, la cantidad de materia que hay en el Universo es 3,53x10⁵⁴ kg.

2. La masa del sol es 2x10³⁰ kg, por lo que para completar la masa total del Universo visible se necesitan las siguientes masas solares:

[tex]N = \frac{m_{u}}{m_{s}} = \frac{3,53 \cdot 10^{54} kg}{2\cdot 10^{30} kg} = 1,8 \cdot 10^{24}[/tex]

Por lo tanto, se necesitan 1,8x10²⁴ masas solares para completar la masa total del Universo visible.

Espero que te sea de utilidad!  

Answer:

i think b

Explanation:

i'm not sure

Answer:

I think both pure substance and an element .

hope it is helpful to you ☺️☺️

Answer:

The volume displacement resulting from the action, minus the original volume.

Answer: I really don’t know

Explanation:

Answer:

p=mv

p=given=24500kg-m/sec

m=?

v=20m/sec

m=p/v

=24500kg-m/sec÷20m/sec

=1225kg=ans

Answer:

1225kg=ans

Explanation:

Answer:

At maximum  the  current is 4A and resistance is 55Ω

At minimum the current is 1.636A and resistance is 134.45Ω

Explanation:

The computation of the current and the resistance in each case is shown below:

At the time when it is heated at max rate,

power, P = 840W

V = 220V

As We know that

P = VI

840 = 220 × I

I = 840 ÷ 220

I = 4 A

Now

R = V ÷ I

= 220 ÷4

= 55 Ω

Hence, the  current is 4A and resistance is 55Ω

At the time When it is heated at minimum rate,

power, P = 360W

V = 220V

As We know that

P = VI

360 = 220 × I

I = 360 ÷ 220

I = 1.636 A

Now

R = V÷ I

= 220 ÷1.636

= 134.45 Ω

Hence, the current is 1.636A and resistance is 134.45Ω

Answer:

Chemical energy to heat energy to kinetic energy to electrical energy

Answer:

I think the answer is Milky Way

I hope this Will help you

Answer:

the center of the universe is in your mom's stomach. why do I keep seeing people wanting to look for a date. the f. u. c. k.?

Explanation:

Mitochondria are essential parts of many eukaryotes, but they are useless without oxygen. Therefore, chloroplasts are extremely important. They produce breathable air for life. Root hairs are seen to not have chloroplasts as their job is to collect water and nutrients.

Answer:

63360 mi/h

Explanation:

How to find the speed of an object

Calculate speed, distance, or time using the formula d = st, distance equals speed times time. The Speed Distance Time Calculator can solve for the unknown SDT value given two known values.

Time can be entered or solved for in units of second S (s), minutes (min), hours (hr), or hours and minutes and seconds (hh:mm: ss). See shortcuts for time formats below.

To solve for distance use the formula for distance D = st, or distance equals speed times time.

distance = speed x time

Rate and speed are similar since they both represent some distance per unit time like miles per hour or kilometers per hour. If rate r is the same as speed s, r = s = d/t. You can use the equivalent formula d = rt which means distance equals rate times time.

distance = rate x time

To solve for speed or rate use the formula for speed, s = d/t which means speed equals distance divided by time.

speed = distance/time

To solve for time use the formula for time, t = d/s which means time equals distance divided by speed.

time = distance/speed

Therefore, the speed = 63360 miles per hour

= 63360 mi/h

Answer:

1. An autotroph

2. Domain

3. Reproduction

4. Kingdom

5. Multicellular Organism

6. Genetic trait

Explanation: Took Bio honors 1 & 2

Answer:

B They react with all metals producing hydrogen.

Answer:

the correct one is B

Explanation:

In this exercise, indicate that crocodiles need a warm climate to survive.

The current climate in the western Colorado region where the temperature is 53ºF (11.7ºC) does not allow them to survive, therefore the appearance of fossil crocodiles and fossil subtropical plants and a clear indication that the climate in these regions was much more warm

when checking the answers the correct one is B

Answer:

Time = 3.2 seconds

Explanation:

Given the following data;

Weight = 635 N

Height, h = 2.43 m

Power = 482 Watts

To find the time;

Power = mgh/time

But weight = mg = 635

Substituting into the formula, we have;

482 = (635 * 2.43)/time

482 = 1543.05/time

Time = 1543.05/482

Time = 3.2 seconds